Rinse fish, cut into four to six pieces and dry with paper towels. Set aside.

In a bowl, prepare the potato starch seasoned with salt and pepper. Toss the fish in the potato starch until fully coated.

Prepare a saucepan with two tablespoons oil on medium heat. Place the fish in the pan to lightly sear.

Carefully flip over after two to three minutes. Set aside on a plate.

Add the onion and sauté until softened.

Add tomato sauce, paste, pepper, tomatoes, and cumin. Stir to combine and heat thoroughly. Add 1/4 cup water if too thick.

Add the fish back into the saucepan. Lightly coat the fish with the sauce and cook on low for 15 minutes. Add cilantro and lime if desired for a finishing touch.